There are various instances where indoor or outdoor events require seating for a viewing audience. Permanent seating, such as bleachers, is often provided for recurring events that are frequently held in the same place. Permanent bleachers typically employ a lower framework that supports and interconnects a plurality of generally parallel longitudinally extending bleacher seats. The framework typically includes longitudinally spaced laterally extending base members which provide ground support for the framework and seats.
Alternatively, for many one-time events or events that are less frequent, temporary seating such as portable bleachers are often employed. Portable bleachers are also often used to supplement existing permanent seating to increase seating capacity, if desired, for larger events. A desirable characteristic of such portable seating is that the mobile framework carrying the seating be user friendly and that the framework limit the effort involved in moving and positioning the bleacher.
Mobile frameworks, or portable bleacher apparatus, are known in which one section of the seating is permanently fixed to a wheeled framework and at least one other section of seating is pivotably mounted thereto. The apparatus forms a trailer which is pulled by, for example, a truck or utility vehicle. Hydraulic cylinders or other mechanical devices are often used to pivot the movable section between a nested, travel position and an operative, seating position. In order to stabilize and level the bleacher prior to use, a plurality of individually operated jacks are installed along each side of the framework. In operation, the operator must swivel each jack into a storage mode, and then each jack must be manually cranked from a squatting or kneeling position to adjust for the particular terrain. This necessitates that an operator expend a great deal of time and energy adjusting the jacks on each side of the framework.
It is therefore desirable to provide a means for transporting bleacher framework which does not require separate individual lifting means on each side of the bleacher framework. It is desirable to provide a bleacher transporting system, or trailer apparatus, which is simple to install and operate and which may be operated by a single person, thus limiting the labor intensive efforts required to maneuver and set up the bleacher framework. In addition, it is desirable to provide a trailer apparatus which employs a single lifting unit, such that the bleacher may be lifted and transported from one side of the bleacher by a single operator. Further, it is desirable to provide a trailer apparatus which may be used with a variety of stationary existing bleacher framework configurations.